Auto-switching List Search Interface for Touchscreen Smartwatches

As smartwatch functions expand, target selection among many items will probably become a common task. List search interfaces (LSIs) for a smartwatch use a prefix matching query to search for items, and need two modes because of the small screen size: query input mode and list navigation mode. Despite the modes, LSIs may be more efficient than list interfaces (LIs), which involve no text querying, for large pools. Actually, we could show that the LSI outperformed the LI for pool sizes over 60. However, we also found that the LSI users experience overhead when deciding whether to switch the modes or not. To reduce the overhead, we designed two auto-switching LSIs: input-length-based auto-switching LSI (IA-LSI) and list-size-based auto-switching LSI (LA-LSI). We could show both auto-switching LSIs outperformed the conventional LSI for pool sizes over 60. We also conducted experiments with the auto-switching LSIs for various pool sizes, and provided their results and guidelines for the optimal switching criteria for the LSIs.